Lab animals such as mice are critical tools for understanding the disease development, testing drug candidates, and devising treatments. In spite of the vast amount of knowledge generated, molecular biology assays on mice have mostly been done via ensemble measurements of the average properties of a group. However, similar to the rationale behind single molecule studies, ensemble averages often bury important details about the dynamics and ignore population heterogeneity and subsets. In this project, we will study the temporal dynamics in gene regulations during disease development (i.e. endotoxemia-induced atherosclerosis) based on single live animal experiments. We will develop ultrasensitive microfluidic ChIP-qPCR and ChIP- seq assays for testing based on tiny amounts of blood samples from mice. In principle these tests can be minimally invasive and do not perturb the state of the animal and the disease process. We will be able to conduct periodical examination of the same live mouse over the course of the disease development and understand the temporal dynamics in the transcription factor/promoter bindings and histone modifications. We believe that the single live animal data will grant unique insights into the molecular events involved in these biological processes and provide important basis for diagnosis, prognosis, drug design/discovery, and treatment strategy. Such data also most closely mimic what occurs in human patients during disease development and treatment, thus offer direct clinical relevance.